Infertility and neonatal mortality in the sow I. Lifetime performance and reasons for disposal of sows

Abstract

1. A survey of the reasons for disposal of 1000 sows from farms in a selected area of East Anglia showed that the most important causes of sow wastage were ‘failure to breed’, ‘piglet mortality’, ‘old age’ and ‘low fertility’ which together accounted for 64·3% of the sows.2. The average length of breeding life was 3·75 litters per sow and the modal number of litters was only two. This expectation of life is very short but is in agreement with an earlier estimate based on Breed Society records.3. Failure to breed was the most important cause of sow wastage and accounted for 21·4% of the sows. The incidence of reproductive failure was greatest in young sows and of all the sows discarded as sterile 30·3% were discarded after having had only one litter. Cases of failure to breed were divisible into two broad groups.